Rafael Nadal

Serena Williams will be back on court Friday, facing Yaroslava Shvedova in the nightcap at Arthur Ashe Stadium. Former champs Novak Djokovic and Andy Murray also have matches, while two other US Open winners, Juan Martin del Potro and Lleyton Hewitt, play each other.

Federer’s second-round loss at Wimbledon, a year after taking the title, drops him from No. 3. He was fifth in the rankings on June 23, 2003, two weeks before he won Wimbledon for the first of his record 17 major championships.

In one of Wimbledon’s greatest upsets, an ailing Rafael Nadal was knocked out in straight sets on Monday by a player ranked 135th — the Spaniard’s first loss in the opening round of a Grand Slam event.

Yes, the ingredients are in place for the torch to finally be passed — at least for the moment — to a new men’s Grand Slam champion. And if it does play out that way, what will it feel like? It’s tough to say, as there has only been one blip on the Big Three’s radar since 2005.

The four-time Grand Slam champion lost to 18-year-old Laura Robson of Britain in the second round of the U.S. Open on Wednesday, and will head into retirement after she finishes playing in doubles at Flushing Meadows.